Modified organic silicon defoaming agent for water-based paint ink and preparation method of modified organic silicon defoaming agent

Abstract

According to the modified organic silicon defoaming agent for the water-based paint ink and the preparation method of the modified organic silicon defoaming agent, a part of allyl polyether is grafted on an active matter, so that the compatibility of the active matter in the paint ink is improved; the active matter is dispersed at a high speed, so that the filler is more uniformly distributed in the active matter, the product stability is improved, the effect of foam breaking particles is maximized, and a good foam eliminating and inhibiting effect is achieved under the condition of low addition amount; and the emulsion is prepared through high-speed dispersion, so that active matters can be emulsified into small enough particles, and the compatibility of the product in an application system is improved.

Description

Technical Field

[0001] The present invention relates to a modified silicone defoamer and a preparation method thereof, belonging to the technical field of fine chemicals, and particularly applicable to the preparation method of a modified silicone defoamer for coating and ink systems. Background Art

[0002] Waterborne coatings and inks are highly favored in modern industry due to their environmental friendliness and low VOC content. However, during the production and application processes, foam problems often lead to a decline in quality and a reduction in efficiency. Traditional defoamers such as silicone-based ones are highly efficient but have compatibility problems; while non-silicone-based defoamers have limited defoaming effects. Modified silicone defoamers, through structural optimization, have improved dispersibility and compatibility in waterborne systems while maintaining high defoaming performance. With the tightening of environmental regulations, the development of highly efficient and environmentally friendly defoamers has become crucial. Modified silicone defoamers have broad application prospects in waterborne coatings and inks, not only solving traditional problems but also meeting environmental requirements.

[0003] CN111871010B provides a silicone defoamer and a preparation method thereof, but there are defects such as a high usage amount of the silicone defoamer and a deterioration in defoaming performance and foam suppression performance at high temperatures. The invention patent of CN110157232A discloses a defoamer special for waterborne environmental protection coatings. This defoamer overly relies on emulsifiers, which will lead to a decline in the stability of the defoamer, affecting its dispersion effect and long-term performance in coatings. Summary of the Invention

[0004] The present invention provides a modified silicone defoamer for waterborne coatings and inks and a preparation method thereof. By grafting a part of allyl polyether onto the active substance, the compatibility of the active substance in coatings and inks is improved; the active substance is treated by high-speed dispersion to make the filler more evenly distributed in the active substance, while improving the product stability, maximizing the role of defoaming particles, and achieving good defoaming and foam suppression effects under low addition amounts; and the emulsion is prepared by high-speed dispersion, which can ensure that the active substance can be emulsified into sufficiently small particles, enhancing the compatibility of the product in the application system.

[0005] The modified silicone defoamer for waterborne coatings and inks described in the present invention is composed of the following components:

[0006] A. Hydrogen-containing silicone oil

[0007] The structural formula of the hydrogen-containing silicone oil is: HMe 2 Si(SiR 1 HO) d (SiR 2 2 O) e SiMe 2 H, R 1 、R 2Same or different, selected from methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl; the subscript d is an integer from 5 to 20, and e is an integer from 50 to 200; the dosage of the hydrogen-containing silicone oil is 4-10% of the total mass of the modified silicone defoamer.

[0008] B. Olefins

[0009] The olefins are any one or a mixture of straight-chain α-olefins, α-aromatic olefins or branched α-olefins, including α-octene, α-decene, α-dodecene, α-tetradecene, α-hexadecene, α-octadecene, α-eicosene, a mixture of straight-chain α-olefins with C20-C24, a mixture of straight-chain α-olefins with C24-C28, α-triacontene, α-methylstyrene, α-styrene, and can be used alone or in any proportion; the dosage of the α-olefin is 5-10% of the total mass of the modified silicone defoamer.

[0010] C. Allyl polyether

[0011] The structural general formula of allyl polyether is as follows:

[0012] CH 2 =CHCH 2 (OCH 2 CH 2 ) b (OCH 2 CHCH 3 ) c OH

[0013] Among them, b is an integer from 1 to 10, and c is an integer from 10 to 100. The dosage of the allyl polyether is 0.1-2% of the total mass of the modified silicone defoamer.

[0014] D. Filler

[0015] The filler is a mixture of MQ resin and fumed silica in any proportion, where the MQ resin is composed of a chain unit R 3 3 SiO l / 2 (referred to as the M unit in organosilicon chemistry) and a chain unit SiO 4 / 2 (referred to as the Q unit in organosilicon chemistry), and the molar ratio between the two is 0.4:1.0-1.2:1.0; in the M unit R 3 3 SiO l / 2 The R in 3 is the same or different, and the value is selected from a hydrogen atom, a monovalent substituted or unsubstituted alkyl group with 1-20 carbon atoms; among them, the fumed silica is specifically selected from those with a specific surface area of 20-500 m 2A mixture of fumed hydrophobic silica and precipitated hydrophobic silica per gram, wherein the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2 - 5:1 - 3. The dosage of the filler is 1 - 5% of the total mass of the modified silicone defoamer.

[0016] E. Silicon polyether

[0017] The silicon polyether is prepared by an addition reaction of a hydrogen-containing polysiloxane and an unsaturated polyether under the action of a catalyst. The specific preparation method can be found in professional technical literature. The kinematic viscosity of the silicon polyether at 25 °C is 10 - 50,000 mPa·s, preferably 50 - 20,000 mPa·s. The structural formula of the silicon polyether is represented by the following general formula:

[0018] (CH 3 ) 3 SiO{(CH 3 ) 2 SiO) x (CH 3 GSiO) y}(CH 3 ) 3 ①

[0019] Among them, G is a polyether group, represented by the following structural general formula:

[0020] -(CH 2 ) z (EO) g (PO) h R ②

[0021] In the above structural formula, R is -H or -CH 3 or -COCH 3 ; the subscripts x, y, z, g, h are degrees of polymerization, x is an integer from 10 to 500; y is an integer from 1 to 50; z is an integer from 2 to 6; g is an integer from 1 to 40; h is an integer from 1 to 60. In the structural formula ①, when G is different allyl alcohol polyether groups, the silicon polyether is a silicon polyether synthesized from multiple polyethers. The dosage of the silicon polyether is 10 - 35% of the total mass of the modified silicone defoamer.

[0022] F. Emulsifier

[0023] The emulsifier is a non-ionic surfactant, selected from polyethylene glycol fatty acid esters, fatty alcohol polyoxyethylene ethers, oleic acid polyoxyethylene ethers, castor oil polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, fatty amine polyoxyethylene ethers, polyoxyethylene sorbitan monolaurate (Tween20), polyoxyethylene sorbitan monopalmitate (Tween40), polyoxyethylene sorbitan monostearate (Tween60), polyoxyethylene sorbitan monooleate (Tween80), polyoxyethylene sorbitan trioleate (Tween85), sorbitan monolaurate (Span20), sorbitan monopalmitate (Span40), sorbitan monostearate (Span60), sorbitan monooleate (Span80), sorbitan trioleate (Span85), or a mixture of one or more thereof. The dosage of the emulsifier is 2-8% of the total amount of the modified silicone defoamer.

[0024] G. Polyether

[0025] The polyether is a saturated polyether, and its general molecular structure formula is as follows:

[0026] R 4 {M(PO) n (EO) m H} a

[0027] In the formula, M is a linking group, which is -O- or -CO-; R 4 is an alcohol or amine initiator, selected from propylene glycol, glycerol, trimethylolpropane, pentaerythritol, xylitol, ethylenediamine, triethylenediamine, sorbitol, sucrose, bisphenol A, bisphenol S, toluenediamine; the subscripts m and n are the polymerization degrees of ethylene oxide (EO) and propylene oxide (PO) respectively, and m and n are integers from 1 to 20; the subscript 1 ≤ a ≤ 3; the molecular weight of the polyether is 2000-6000, and the cloud point is 5-20 °C; the dosage of the polyether is 5-20% of the total mass of the modified silicone defoamer.

[0028] H. Hydrophilic silica

[0029] The hydrophilic silica is selected from fumed hydrophilic silica or precipitated hydrophilic silica, and its specific surface area is 50-380 m 2 / g. The dosage of the hydrophilic silica accounts for 0.5-2% of the total mass of the modified silicone defoamer.

[0030] I. Thickening water

[0031] The thickened water is a mixture of a thickener and water. Among them, the thickener is specifically selected from xanthan gum, guar gum, PVA, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and acrylate esters. The present invention preferably uses an acrylate ester thickener. The water is deionized water. The amount of the thickened water is 35-60% of the total mass of the modified silicone defoamer.

[0032] J. Catalyst

[0033] The catalyst described above is selected from platinum-alcohol complex, platinum-olefin complex, platinum-alcoholate complex, platinum-ether complex, platinum-ketone complex, isopropyl alcohol solution of chloroplatinic acid, platinum-vinyl complex, and stannous octoate. Preferably, an isopropyl alcohol solution of chloroplatinic acid with a platinum content of 1-20 ppm is used. The amount of the catalyst accounts for 0.0001%-0.001% of the total mass of the modified silicone, preferably 0.0005%-0.001%.

[0034] The preparation method of the modified silicone defoamer is as follows:

[0035] (1) Add hydrogen-containing silicone oil A, olefin B, allyl polyether C, and filler D into a reaction vessel and stir evenly. Control the rotation speed at 1000-1500 rpm. After high-speed dispersion for 10 min, heat up to 50-100 °C, add catalyst J, and keep the temperature for 20-60 min after the reaction to obtain active substance K;

[0036] (2) Add active substance K, silicone polyether E, emulsifier F, polyether G, and hydrophilic silica H into a high-speed dispersion device, and control the rotation speed at 1000-1500 rpm for high-speed dispersion for 30-120 min until the system is uniform to obtain mixture L;

[0037] (3) Slowly add thickened water I to mixture L, and at the same time continue to maintain the rotation speed at 1000-1500 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T of the present invention is obtained. Specific embodiments

[0038] The hydrogen-containing silicone oil embodiments of the present invention are as follows:

[0039] Hydrogen-containing silicone oil A-1 A-2 A-3 A-4 A-5 A-6 A-7 <![CDATA[R 1 > Methyl n-Propyl Isobutyl Ethyl Methyl n-Propyl n-Butyl <![CDATA[R 2 > Ethyl n-Butyl n-Amyl n-Butyl Methyl Isobutyl n-Amyl d 5 10 15 20 18 8 12 e 50 80 120 180 200 60 160

[0040] The silicone polyether embodiments of the present invention are as follows:

[0041] Silicone polyether E-1 E-2 E-3 E-4 E-5 E-6 E-7 R <![CDATA[—CH 3 > —H <![CDATA[—CH 3 > <![CDATA[—COCH 3 > <![CDATA[—CH 3 > —H <![CDATA[—CH 3 > x 10 80 120 180 200 300 400 y 2 12 20 26 32 45 50 z 2 4 6 2 4 6 2 g 2 6 10 16 22 34 40 h 2 12 24 30 40 52 60

[0042] The polyether embodiments of the present invention are as follows:

[0043] Polyether M <![CDATA[R 4 > m n a G-1 -O- Propylene glycol 1 1 1 G-2 -CO- Glycerol 2 3 2 G-3 -O- Xylitol 5 5 3 G-4 -CO- Ethylenediamine 6 4 1 G-5 -O- Bisphenol A 10 12 2 G-6 -CO- Triethylenediamine 15 16 3 G-7 -O- Toluenediamine 20 18 1

[0044] Example 1

[0045] (1) Add 4 parts of hydrogen-containing silicone oil A-1, 10 parts of α-octene and α-dodecene, 2 parts of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 2 (OCH 2 CHCH 3 ) 12 OH), 5 parts of filler (the molar ratio of MQ resin is 0.4:1, the specific surface area of silica is 20 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:1) into the reaction vessel, stir evenly, control the rotation speed at 1000 rpm, after high-speed dispersion for 10 min, heat up to 50 °C, add 0.0001 part of platinum-alcohol complex solution, keep warm for 20 - 60 min after the reaction to obtain the active substance K1;

[0046] (2) Add the active substance K1, 10 parts of silicone polyether E-1, 7 parts of the mixture of fatty alcohol polyoxyethylene ether and polyoxyethylene sorbitan monopalmitate (Tween40), 20 parts of polyether G-1, 2 parts of fumed hydrophilic silica (specific surface area is 50 m 2 / g) into the high-speed dispersion equipment, control the rotation speed at 1000 rpm and disperse at high speed for 30 min until the system is uniform to obtain the mixture L1;

[0047] (3) Slowly add the mixture of 40 parts of xanthan gum and deionized water to the mixture L1, while continuing to maintain the rotation speed at 1000 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T1 of the present invention is obtained.

[0048] Example 2

[0049] (1) Add 5 parts of hydrogen-containing silicone oil A-2, 7 parts of α-decene and the straight-chain α-olefin mixture of C20 - C24, 1 part of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 3 (OCH 2 CHCH 3 ) 20 OH), 3 parts of filler (the molar ratio of MQ resin is 0.5:1, the specific surface area of silica is 80 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:3) into the reaction vessel, stir evenly, control the rotation speed at 1200 rpm, after high-speed dispersion for 10 min, heat up to 60 °C, add 0.01 part of chloroplatinic acid isopropanol solution, keep warm for 30 min after the reaction to obtain the active substance K2;

[0050] (2) Add 20 parts of silicone polyether E-2, 4 parts of the mixture of fatty amine polyoxyethylene ether and polyoxyethylene sorbitan monolaurate (Tween20), 9.3 parts of polyether G-2, and 0.69 part of precipitated hydrophilic silica (specific surface area is 80 m 2 / g) into a high-speed dispersion device, control the rotation speed at 1200 rpm, and disperse at high speed for 30 min until the system is uniform to obtain mixture L2;

[0051] (3) Slowly add 50 parts of the mixture of acrylate and deionized water to mixture L2, and at the same time continue to maintain the rotation speed at 1200 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T2 of the present invention is obtained.

[0052] Example 3

[0053] (1) Add 6 parts of hydrogen-containing silicone oil A-3, 6 parts of the mixture of α-triacontene and straight-chain α-olefins of C24-C28, 1.5 parts of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 4 (OCH 2 CHCH 3 ) 30 OH), 4 parts of filler (the molar ratio of MQ resin is 0.5:1, the specific surface area of silica is 80 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:3) into a reaction vessel, stir evenly, control the rotation speed at 1300 rpm, after high-speed dispersion for 10 min, heat up to 70 °C, add 0.005 part of platinum-ether complex, and keep warm for 35 min after the reaction to obtain active substance K3;

[0054] (2) Add active substance K3, 27 parts of silicone polyether E-3, 5 parts of sorbitan monooleate (Span80), 15 parts of polyether G-3, and 0.5 part of fumed hydrophilic silica (specific surface area is 100 m 2 / g) into a high-speed dispersion device, control the rotation speed at 1300 rpm, and disperse at high speed for 50 min until the system is uniform to obtain mixture L3;

[0055] (3) Slowly add 50 parts of the mixture of guar gum and deionized water to mixture L3, and at the same time continue to maintain the rotation speed at 1300 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T3 of the present invention is obtained.

[0056] Example 4

[0057] (1) Add 7 parts of hydrogen-containing silicone oil A-4, 5 parts of α-triacontene, 0.1 part of allyl polyether (CH 2=CHCH 2 (OCH 2 CH 2 ) 5 (OCH 2 CHCH 3 ) 50 (OH), 1 part of filler (the molar ratio of MQ resin is 0.7:1, the specific surface area of silica white is 200 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 5:3) is added to the reaction vessel and stirred evenly. The rotation speed is controlled at 1250 rpm. After high-speed dispersion for 10 min, the temperature is raised to 80 °C, 0.001 part of platinum-alcohol complex is added, and after the reaction, it is kept warm for 40 min to obtain the active substance K4;

[0058] (2) The active substance K4, 27 parts of silicone polyether E-4, 5 parts of sorbitan trioleate (Span85), 5 parts of polyether G-4, and 1 part of precipitated hydrophilic silica white (with a specific surface area of 150 m 2 / g) are added to the high-speed dispersion equipment, and the rotation speed is controlled at 1250 rpm for high-speed dispersion for 60 min until the system is uniform to obtain the mixture L4;

[0059] (3) A mixture of 45.1 parts of sodium carboxymethyl cellulose and deionized water is slowly added to the mixture L4, and at the same time, the rotation speed is continuously maintained at 1250 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T4 of the present invention is obtained.

[0060] Example 5

[0061] (1) 10 parts of hydrogen-containing silicone oil A-5, 5 parts of α-methylstyrene, 1.9 parts of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 6 (OCH 2 CHCH 3 ) 60 (OH), 1 part of filler (the molar ratio of MQ resin is 0.8:1, the specific surface area of silica white is 300 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 3:1) is added to the reaction vessel and stirred evenly. The rotation speed is controlled at 1500 rpm. After high-speed dispersion for 10 min, the temperature is raised to 85 °C, 0.001 part of isopropyl alcohol solution of chloroplatinic acid is added, and after the reaction, it is kept warm for 45 min to obtain the active substance K5;

[0062] (2) Add 22.1 parts of active ingredient K5, 8 parts of silicone polyether E-5, 8 parts of alkylphenol polyoxyethylene ether and polyoxyethylene sorbitan trioleate (Tween85), 10 parts of polyether G-5, and 1.5 parts of precipitated hydrophilic silica (specific surface area is 220 m 2 / g) into a high-speed dispersion device, control the rotation speed at 1500 rpm, and disperse at high speed for 80 min until the system is uniform to obtain mixture L5;

[0063] (3) Slowly add a mixture of 38 parts of hydroxyethyl vitamin and deionized water to mixture L5, and at the same time continue to maintain the rotation speed at 1500 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T5 of the present invention is obtained.

[0064] Example 6

[0065] (1) Add 5 parts of hydrogen-containing silicone oil A-6, 5 parts of α-hexadecene, 0.5 part of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 7 (OCH 2 CHCH 3 ) 70 OH), 1 part of filler (the molar ratio of MQ resin is 1:1, the specific surface area of silica is 400 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 3:2) into the reaction vessel, stir evenly, control the rotation speed at 1350 rpm, after high-speed dispersion for 10 min, heat up to 90 °C, add 0.008 part of platinum-ether complex, and keep warm for 50 min after the reaction to obtain active ingredient K6;

[0066] (2) Add active ingredient K6, 35 parts of silicone polyether E-6, 4 parts of sorbitan monolaurate (Span20), 6 parts of polyether G-6, and 0.8 part of fumed hydrophilic silica (specific surface area is 300 m 2 / g) into a high-speed dispersion device, control the rotation speed at 1350 rpm, and disperse at high speed for 100 min until the system is uniform to obtain mixture L6;

[0067] (3) Slowly add a mixture of 41 parts of methyl cellulose and deionized water to mixture L6, and at the same time continue to maintain the rotation speed at 1350 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T6 of the present invention is obtained.

[0068] Example 7

[0069] (1) Add 8 parts of hydrogen-containing silicone oil A-7, 9 parts of α-hexadecene, 0.5 part of allyl polyether (CH 2 =CHCH 2(OCH 2 CH 2 ) 8 (OCH 2 CHCH 3 ) 80 (OCH), 1 part of filler (the molar ratio of MQ resin is 1.2:1, the specific surface area of silica white is 500 m 2 / g, the ratio of fumed hydrophobic silica white to precipitated hydrophobic silica white is 5:1) was added to the reaction vessel and stirred evenly. The rotation speed was controlled at 1400 rpm. After high-speed dispersion for 10 min, the temperature was raised to 100 °C, and 0.002 part of chloroplatinic acid isopropanol solution was added. After the reaction, it was kept warm for 60 min to obtain the active substance K7;

[0070] (2) The active substance K7, 12 parts of silicone polyether E-7, 2 parts of sorbitan monopalmitate (Span40), 5 parts of polyether G-7, 1.2 parts of fumed hydrophilic silica white (specific surface area is 380 m 2 / g) were added to the high-speed dispersion equipment, and the rotation speed was controlled at 1400 rpm for high-speed dispersion for 120 min until the system was uniform to obtain the mixture L7;

[0071] (3) A mixture of 38 parts of methyl cellulose and deionized water was slowly added to the mixture L7, and at the same time, the rotation speed was continuously maintained at 1400 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T7 of the present invention was obtained.

[0072] Comparative Example 1

[0073] (1) 4 parts of hydrogen-containing silicone oil A-1, 10 parts of α-octene and α-dodecene, 2 parts of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 2 (OCH 2 CHCH 3 ) 12 (OH), 5 parts of filler (the molar ratio of MQ resin is 0.4:1, the specific surface area of silica white is 20 m 2 / g, the ratio of fumed hydrophobic silica white to precipitated hydrophobic silica white is 2:1) was added to the reaction vessel and stirred evenly. The rotation speed was controlled at 1000 rpm. After high-speed dispersion for 10 min, the temperature was raised to 50 °C, and it was kept warm for 20 - 60 min to obtain the active substance K8;

[0074] (2) The active substance K8, 10 parts of silicone polyether E-1, 7 parts of a mixture of fatty alcohol polyoxyethylene ether and polyoxyethylene sorbitan monopalmitate (Tween40), 20 parts of polyether G-1, 2 parts of fumed hydrophilic silica white (specific surface area is 50 m 2(g) was added to a high-speed dispersion device, and the rotation speed was controlled at 1000 rpm for high-speed dispersion for 30 min until the system was uniform, obtaining mixture L8;

[0075] (3) A mixture of 40 parts of xanthan gum and deionized water was slowly added to mixture L8, while continuing to maintain the rotation speed at 1000 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T8 of the present invention was obtained.

[0076] Comparative Example 2

[0077] (1) 5 parts of hydrogen-containing silicone oil A-2, 7 parts of α-decene and a mixture of linear α-olefins of C20-C24, 3 parts of fillers (the molar ratio of MQ resin is 0.5:1, the specific surface area of silica is 80 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:3) were added to a reaction vessel and stirred evenly. The rotation speed was controlled at 1200 rpm. After high-speed dispersion for 10 min, the temperature was raised to 60 °C, and 0.01 part of chloroplatinic acid isopropanol solution was added. After the reaction, it was kept warm for 30 min to obtain active substance K9;

[0078] (2) Active substance K2, 20 parts of silicone polyether E-2, 4 parts of a mixture of fatty amine polyoxyethylene ether and polyoxyethylene sorbitan monolaurate (Tween20), 9.3 parts of polyether G-2, 0.69 part of precipitated hydrophilic silica (specific surface area is 80 m 2 / g) were added to a high-speed dispersion device, and the rotation speed was controlled at 1200 rpm for high-speed dispersion for 30 min until the system was uniform, obtaining mixture L9;

[0079] (3) A mixture of 51 parts of acrylate and deionized water was slowly added to mixture L9, while continuing to maintain the rotation speed at 1200 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T9 of the present invention was obtained.

[0080] Comparative Example 3

[0081] (1) 5 parts of hydrogen-containing silicone oil A-2, 7 parts of α-decene and a mixture of linear α-olefins of C20-C24, 1 part of commercially available linear unsaturated polyether, 3 parts of fillers (the molar ratio of MQ resin is 0.5:1, the specific surface area of silica is 80 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:3) were added to a reaction vessel and stirred evenly. The rotation speed was controlled at 1200 rpm. After high-speed dispersion for 10 min, the temperature was raised to 60 °C, and 0.01 part of chloroplatinic acid isopropanol solution was added. After the reaction, it was kept warm for 30 min to obtain active substance K10;

[0082] (2) Add 20 parts of silicone polyether E-2, 4 parts of the mixture of fatty amine polyoxyethylene ether and polyoxyethylene sorbitan monolaurate (Tween20), 9.3 parts of polyether G-2, and 0.69 part of precipitated hydrophilic silica (specific surface area 80 m 2 / g) to the active ingredient K2 into a high-speed dispersion device, control the rotation speed at 1200 rpm, and disperse at high speed for 30 min until the system is uniform to obtain mixture L10;

[0083] (3) Slowly add 50 parts of the mixture of acrylate and deionized water to mixture L10, and at the same time continue to maintain the rotation speed at 1200 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T10 of the present invention is obtained.

[0084] Comparative Example 4

[0085] (1) Add 6 parts of hydrogen-containing silicone oil A-3, 6 parts of the mixture of α-triacontene and straight-chain α-olefins of C24-C28, 1.5 parts of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 4 (OCH 2 CHCH 3 ) 30 OH), 4 parts of filler (the molar ratio of MQ resin is 0.5:1, the specific surface area of silica is 80 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:3) into the reaction vessel, stir evenly, control the rotation speed at 200 rpm, disperse at high speed for 10 min, then heat up to 70 °C, add 0.005 part of platinum-ether complex, and keep the temperature for 35 min after the reaction to obtain active ingredient K11;

[0086] (2) Add 27 parts of silicone polyether E-3, 5 parts of sorbitan monooleate (Span80), 15 parts of polyether G-3, and 0.5 part of fumed hydrophilic silica (specific surface area 100 m 2 / g) to the active ingredient K3 into a high-speed dispersion device, control the rotation speed at 200 rpm, and disperse at high speed for 50 min until the system is uniform to obtain mixture L11;

[0087] (3) Slowly add 50 parts of the mixture of guar gum and deionized water to mixture L11, and at the same time continue to maintain the rotation speed at 200 rpm for high-speed dispersion. After uniform dispersion, the modified silicone defoamer T11 of the present invention is obtained.

[0088] Comparative Example 5

[0089] (1) Add 6 parts of hydrogen-containing silicone oil A-3, 6 parts of α-triacontene, and a mixture of linear α-olefins with C24 - C28, 1.5 parts of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 4 (OCH 2 CHCH 3 ) 30 OH), 4 parts of filler (the molar ratio of MQ resin is 0.5:1, the specific surface area of silica is 80 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 2:3) into the reaction vessel, stir evenly, heat up to 70 °C, add 0.005 parts of platinum-ether complex, keep warm for 35 min after the reaction to obtain the active substance K12;

[0090] (2) Add the active substance K3, 27 parts of silicone polyether E-3, 5 parts of sorbitan monooleate (Span80), 15 parts of polyether G-3, 0.5 parts of fumed hydrophilic silica (specific surface area is 100 m 2 / g) into the reactor, stir evenly to obtain the mixture L12;

[0091] (3) Slowly add a mixture of 50 parts of guar gum and deionized water to the mixture L12, and at the same time continue to maintain a high-speed dispersion at a rotation speed of 200 rpm. After uniform dispersion, the modified silicone defoamer T12 of the present invention is obtained.

[0092] Comparative Example 6

[0093] (1) Add 7 parts of hydrogen-containing silicone oil A-4, 5 parts of α-triacontene, 0.1 part of allyl polyether (CH 2 =CHCH 2 (OCH 2 CH 2 ) 5 (OCH 2 CHCH 3 ) 50 OH), 1 part of filler (the molar ratio of MQ resin is 0.7:1, the specific surface area of silica is 200 m 2 / g, the ratio of fumed hydrophobic silica to precipitated hydrophobic silica is 5:3), 0.001 part of platinum-alcohol complex, 27 parts of silicone polyether E-4, 5 parts of sorbitan trioleate (Span85), 5 parts of polyether G-4, 1 part of precipitated hydrophilic silica (specific surface area is 150 m 2 / g), 45.1 parts of a mixture of sodium carboxymethyl cellulose and deionized water into the reactor, stir evenly to obtain the modified silicone defoamer T13 of the present invention.

[0094] Performance Test

[0095] (1)Compatibility test

[0096] Test method: Add 85 g of green ink into a cup, add 0.3 g of the defoamer to be tested, use a laboratory high-speed disperser to disperse at a speed of 1000 rpm for 5 min, then use a dropper to suck an appropriate amount of ink and drop it on a spreading wheel to coat on a black and white cardboard. Observe the state of the coating and represent it with a grade. The higher the grade, the better the compatibility.

[0097] Classification of coating grades:

[0098]

[0099] Results of compatibility test:

[0100]

[0101] From the above data, it can be seen that the defoamer of the present invention will not cause coating defects, while the defoamer that does not contain allyl polyether, or polyether outside the allyl polyether structure, and the defoamer prepared without using a high-speed dispersion process will cause coating defects.

[0102] (2)Centrifugal stability test

[0103] Test method: Put the defoamer into a graduated centrifuge tube and centrifuge at a high speed of 3000 rpm for 15 min. After centrifugation, observe whether the emulsion in the centrifuge tube is stratified.

[0104]

[0105] (3)Defoaming and antifoaming performance test

[0106] In a 500 ml graduated cylinder, put 110 g of the self-made ink sample for testing, with the defoamer addition amount of 3.5‰, put it into a gas drum device, adjust the flow rate to 1 L / min, turn on the gas drum to continuously blow air into the graduated cylinder, record the change rule of the foam volume V with time t; fix the gas drum time and compare the foam height.

[0107] Unit: mL

[0108]

Claims

1. A method for preparing a modified silicone defoamer for water-based coating ink, characterized in that: It is composed of the following components: The amount of hydrogenated silicone oil in component A is 4-10% of the total mass of the modified silicone defoamer for water-based coatings and inks; The amount of olefin in component B is 5-10% of the total mass of the modified silicone defoamer for water-based coatings and inks; The dosage of component C allyl polyether is 0.1-2% of the total weight of the modified silicone defoamer for water-based coatings and inks; The amount of filler in component D is 1 to 5% of the total mass of the modified silicone defoamer for water-based coatings and inks; The amount of component E silicone polyether is 10-35% of the total mass of the modified silicone defoamer for water-based coatings and inks; The amount of emulsifier in component F is 2-8% of the total mass of the modified silicone defoamer for water-based coatings and inks; The amount of component G polyether is 5-20% of the total mass of the modified silicone defoamer for water-based coatings and inks; The amount of hydrophilic white carbon black in component H is 0.5-2% of the total mass of the modified silicone defoamer for water-based coatings and inks; The amount of thickening water in component I is 35-60% of the total mass of the modified silicone defoamer for water-based coatings and inks; The dosage of component J catalyst is 0.0001 to 0.001% of the total mass of the modified silicone defoamer for water-based coatings and inks; The preparation method of the modified silicone defoamer for water-based coating ink is as follows: (1) Add hydrogenated silicone oil A, olefin B, allyl polyether C and filler D into a reaction vessel and stir evenly. Control the speed at 1000-1500 rpm. After high-speed dispersion for 10 minutes, heat to 50-100°C, add catalyst J, and keep warm for 20-60 minutes after reaction to obtain active material K. (2) Add active substance K, silicone polyether E, emulsifier F, polyether G, and hydrophilic silica H into a high-speed dispersing device, control the speed at 1000-1500 rpm, and disperse at high speed for 30-120 min until the system is uniform, to obtain a mixture L; (3) Slowly add thickening water I into the mixture L while continuing to disperse at a high speed of 1000 to 1500 rpm. After uniform dispersion, the modified silicone emulsion T of the present invention is obtained.

2. The method for preparing a modified organic silicon defoamer for water-based coating ink according to claim 1, characterized in that the structural formula of the hydrogenated silicone oil in component A is: HMe2Si(SiR 1 HO) d (SiR 2 2O) e SiMe2H,R 1 , R 2 are the same or different and are selected from methyl, ethyl, n-propyl, n-butyl, isobutyl and n-pentyl; the subscript d is an integer of 5-20, and e is an integer of 50-200.

3. A method for preparing a modified organosilicon defoamer for water-based coating ink as claimed in claim 1, characterized in that the component B olefin is a mixture of any one or more of straight-chain α-olefins, α-aromatic olefins or branched α-olefins, including α-octene, α-decene, α-dodecene, α-tetradecene, α-hexadecene, α-octadecene, α-eicosene, a C20-C24 straight-chain α-olefin mixture, a C24-C28 straight-chain α-olefin mixture, α-triacontene, α-methylstyrene, and α-styrene, which can be used alone or mixed in any proportion.

4. The method for preparing a modified silicone defoamer for water-based coating ink according to claim 1, characterized in that the general structural formula of the component C allyl polyether is as follows: CH2=CHCH2(OCH2CH2) b (OCH2CHCH3) c OH in, b is an integer of 1-10, and c is an integer of 10-100.

5. The method for preparing a modified organic silicon defoamer for water-based coating ink according to claim 1, characterized in that the filler of component D is a mixture of MQ resin and white carbon black, wherein the MQ resin is composed of chain segments R 3 3SiO l / 2 (called M unit in silicone chemistry) and chain SiO 4 / 2 The MQ resin is composed of (referred to as Q unit in organosilicon chemistry), and the molar ratio between the two is 0.4:1.0 to 1.2:1.0; the M unit R 3 3SiO l / 2 R 3 The same or different, the value is selected from hydrogen atom, monovalent substituted or unsubstituted alkyl with 1 to 20 carbon atoms; wherein white carbon black is specifically selected from 2 / g of a mixture of fumed hydrophobic silica and precipitated hydrophobic silica, wherein the ratio of the fumed hydrophobic silica to the precipitated hydrophobic silica is 2-5:1-3.

6. The method for preparing a modified organosilicon defoamer for water-based coating ink according to claim 1, characterized in that the component E silicone polyether is prepared by an addition reaction between hydrogen-containing polysiloxane and unsaturated polyether under the action of a catalyst, and the specific preparation method can be found in professional technical literature. The kinematic viscosity of the silicone polyether at 25°C is 10 to 50,000 mPa·s, preferably 50 to 20,000 mPa·s. The structural formula of the silicone polyether is represented by the following general formula: <h2 style=";text-align:left;direction:ltr">(CH3)3SiO{(CH3)2SiO)<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> (CH3GSiO)<h2 style=";text-align:left;direction:ltr"> y <h2 style=";text-align:left;direction:ltr">}(CH3)3① in, G is a polyether group, which is represented by the following general structural formula: -(CH2) z (IS) g (PO) h R 2 In the above structural formula, R is -H or -CH3 or -COCH3; subscripts x, y, z, g, h are polymerization degrees, x is an integer of 10 to 500; y is an integer of 1 to 50; z is an integer of 2 to 6; g is an integer of 1 to 40; h is an integer of 1 to 60. In structural formula ①, G is a different acryl polyether group, and the silicone polyether is a silicone polyether synthesized from multiple polyethers.

7. The method for preparing a modified organic silicon defoamer for water-based coating ink according to claim 1, characterized in that the component F emulsifier is a nonionic surfactant selected from polyethylene glycol fatty acid esters, fatty alcohol polyoxyethylene ethers, oleic acid polyoxyethylene ethers, castor oil polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, fatty amine polyoxyethylene ethers, polyoxyethylene sorbitan monolaurate (Tween 20), polyoxyethylene sorbitan monopalmitate (Tween 40), polyoxyethylene sorbitan monolaurate (Tween 50), polyoxyethylene sorbitan monopalmitate (Tween 60), polyoxyethylene sorbitan monolaurate (Tween 70), polyoxyethylene sorbitan monolaurate (Tween 80), polyoxyethylene sorbitan monolaurate (Tween 90), polyoxyethylene sorbitan monolaurate (Tween 10 ... A mixture of one or more of sorbitan monostearate (Tween 60), polyoxyethylene sorbitan monooleate (Tween 80), polyoxyethylene sorbitan trioleate (Tween 85), sorbitan monolaurate (Span 20), sorbitan monopalmitate (Span 40), sorbitan monostearate (Span 60), sorbitan monooleate (Span 80), and sorbitan trioleate (Span 85).

8. The method for preparing a modified organosilicon defoamer for water-based coating ink according to claim 1, characterized in that the polyether of component G is a saturated polyether, and its molecular structure is as follows: R 4 {M(PO) n (IS) m H} a In the formula, M is a connecting group, which is -O- or -CO-; R 4 The initiator is an alcohol or amine, selected from propylene glycol, glycerol, trimethylolpropane, pentaerythritol, xylitol, ethylenediamine, triethylenediamine, sorbitol, sucrose, bisphenol A, bisphenol S, toluene diamine; the subscripts m and n are the polymerization degrees of ethylene oxide (EO) and propylene oxide (PO), respectively, and m and n are integers of 1 to 20; the subscript 1≤a≤3; the molecular weight of the polyether is 2000 to 6000, and the cloud point is 5 to 20°C.

9. The method for preparing a modified organosilicon defoamer for water-based coatings and inks according to claim 1, characterized in that the hydrophilic silica of component H is selected from fumed hydrophilic silica or precipitated hydrophilic silica, and has a specific surface area of ​​50 to 380 m 2 / g.

10. The method for preparing a modified organosilicon defoamer for water-based coating ink according to claim 1, characterized in that the thickening water of component I is a mixture of a thickener and water, wherein: The thickener is specifically selected from xanthan gum, guar gum, PVA, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and acrylates, and the present invention prefers acrylate thickeners. Water is deionized water.

11. The method for preparing a modified organosilicon defoamer for water-based coating ink according to claim 1, characterized in that the component J catalyst is selected from platinum-alcohol complex, platinum-olefin complex, platinum-alkoxide complex, platinum-ether complex, platinum-ketone complex, chloroplatinic acid isopropanol solution, platinum-vinyl complex, and stannous octoate.

12. The method for preparing a modified silicone defoamer for water-based coating ink according to claim 1, characterized in that the thickener is preferably an acrylic thickener.

13. The method for preparing a modified organosilicon defoamer for water-based coating ink according to claim 1, characterized in that the catalyst J is further preferably a chloroplatinic acid isopropanol solution with a platinum content of 1 to 20 ppm.

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