Water-based ink high-efficiency defoaming agent, preparation method and application thereof

Abstract

The application relates to the fine chemical technology field and discloses a water-based ink high-efficiency defoaming agent and a preparation method and application thereof, the defoaming agent is made of 40-80 parts of end-polyether modified polysiloxane, 10-50 parts of polyether modified heptamethyltrisiloxane, 0.2-10 parts of organic polysilazane resin and 1-15 parts of hydrophobic modified fumed nano silicon dioxide in terms of weight fractions, the preparation raw materials make the water-based ink high-efficiency defoaming agent of the application have very strong defoaming capacity, and foam generated in each production link and the use process of the water-based ink can be effectively controlled by using very low dosage. In addition, the defoaming agent has long-acting property, one-time addition can meet the needs of foam control in the whole water-based ink production and use cycle, and manual work and cost are greatly saved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fine chemical industry, and particularly relates to a water-based ink efficient defoamer and a preparation method and application thereof. BACKGROUND

[0002] Water-based ink is a printing ink with water as a dispersion medium, which is mainly composed of water-soluble / water-dispersible resin, organic pigment, solvent and related additives through complex grinding processing. Compared with other types of ink, water-based ink has the advantages of green environmental protection, low cost, low VOCs emission, no solvent residue, high safety, etc., and is particularly suitable for strict packaging printing products such as tobacco, wine, food, beverage, medicine, children's toys, sanitary products, etc.

[0003] Water-based ink mainly uses water as a diluent. Compared with solvent-based printing ink, water-based ink has the problems of high surface tension and difficulty in wetting non-absorptive substrates, especially low surface energy film substrates (PP, PE, PET). Therefore, a large amount of emulsifier and wetting agent is used in water-based ink to reduce the surface tension of the system. In addition, the main pure acrylic and styrene-acrylic resin emulsion used in water-based ink is used as a film-forming resin, and a large amount of anionic-nonionic emulsifier is used as a resin stabilizing / dispersing aid during the polymerization process of the related resin; a large amount of dispersant and wetting agent is also used as a wetting dispersant for pigments and fillers during the grinding process of the pigments and fillers; especially when printing low surface energy film substrates, in order to obtain sufficient wettability on the surface of the substrate, a large amount of organic silicon wetting agent with extremely low surface tension (≤21 mN / m) is used in the water ink system. The large amount of emulsifier, wetting agent and dispersant used in the production process of water-based ink leads to the fact that water ink is extremely prone to foam, and therefore, foam control becomes the focus of each link from resin synthesis, color paste grinding, ink preparation, high-speed printing, sewage treatment, etc.

[0004] The related art discloses a water ink defoamer prepared by compounding a terminal hydrogen-containing polysiloxane, an allyl alcohol polyether, a catalyst, hydrophobic particles, and an alkyne alcohol modified polysiloxane with a neutral symmetrical structure. The defoamer has good foam control performance and good system compatibility. However, the defoamer prepared by the method has poor durability and poor ability to eliminate fine bubbles in viscous systems.

[0005] The related technology discloses a water-based ink defoaming agent prepared from 42-48 parts of silicone oil, 14-20 parts of hydrophobic silicon dioxide, 14-18 parts of silicone paste, 10-20 parts of high carbon alcohol, 1-3 parts of glycerin fatty acid ester, 3-5 parts of sodium hexametaphosphate, 1-2 parts of sodium secondary alkyl sulfonate, 4-10 parts of magnesium hydroxide, 5-11 parts of dimerized linoleic acid, 5-7 parts of white carbon black, 4-8 parts of white mineral oil, 8-14 parts of surfactant, 20-30 parts of polyethylene wax, 10-12 parts of lecithin, 7-18 parts of thickening agent, 4-14 parts of co-emulsifier, 16-20 parts of distearyl diethylamine and 90-110 parts of deionized water, realizes good dispersibility, strong affinity and fast elimination of fine bubbles of the product, but the defoaming agent prepared by the method has the problems of poor durability and limited export due to the use of white mineral oil.

[0006] Therefore, how to develop a water-based ink efficient defoaming agent with good system compatibility, extremely low addition amount, fast defoaming and long-lasting foam inhibition by technical innovation and apply it in water-based ink, water-based paint, water-based gloss oil and other systems is a problem to be solved at present. SUMMARY

[0007] The present application provides a water-based ink efficient defoaming agent, a preparation method and application thereof, so as to solve one or more technical problems in the prior art and at least provide a beneficial choice or create conditions.

[0008] To overcome the above technical problems, the first aspect of the present application provides a water-based ink efficient defoaming agent.

[0009] The present application also provides a preparation method of the above water-based ink efficient defoaming agent.

[0010] The present application also provides the application of the above water-based ink efficient defoaming agent

[0011] The first aspect of the present application provides a water-based ink efficient defoaming agent, and the preparation raw materials include end polyether modified polysiloxane, polyether modified heptamethyltrisiloxane, organic polysilazane resin and hydrophobic modified fumed nano silicon dioxide.

[0012] The end polyether modified polysiloxane has the following structure:

[0013] ,

[0014] In the formula, R is -(CH2)3(OCH(CH3)CH2) a (OCH2CH2) b OH, n is 5-80, a is 5-15, and b is 0-5.

[0015] The polyether modified heptamethyltrisiloxane has the following structure:

[0016] ,

[0017] wherein Y is -(CH2)3(OCH(CH3)CH2) e (OCH2CH2) f OH, e is 5-15, and f is 0-5.

[0018] According to some embodiments of the present application, the preparation raw materials include 40-80 parts by weight of the end polyether-modified polysiloxane.

[0019] Preferably, the preparation raw materials include 50-70 parts by weight of the end polyether-modified polysiloxane.

[0020] According to some embodiments of the present application, the preparation raw materials include 10-50 parts by weight of the polyether-modified heptamethyltrisiloxane.

[0021] Preferably, the preparation raw materials include 25-45 parts by weight of the polyether-modified heptamethyltrisiloxane.

[0022] According to some embodiments of the present application, the preparation raw materials include 0.2-10 parts by weight of the organopolysilazane resin.

[0023] Preferably, the preparation raw materials include 0.5-3 parts by weight of the organopolysilazane resin.

[0024] According to some embodiments of the present application, the preparation raw materials include 1-15 parts by weight of the hydrophobically-modified fumed nanosilica.

[0025] Preferably, the preparation raw materials include 3-8 parts by weight of the hydrophobically-modified fumed nanosilica.

[0026] The second aspect of the present application provides a method for preparing the above-mentioned water-based ink high-efficiency defoamer. The end polyether-modified polysiloxane, the polyether-modified heptamethyltrisiloxane, and the organopolysilazane resin are first reacted, and then the hydrophobically-modified fumed nanosilica is added and uniformly mixed to prepare the water-based ink high-efficiency defoamer of the present application.

[0027] According to some embodiments of the present application, the organopolysilazane resin is added dropwise under nitrogen protection.

[0028] According to some embodiments of the present application, the dropwise adding time of the organopolysilazane resin is 10-15 min.

[0029] According to some embodiments of the present application, the reaction is carried out under heating.

[0030] According to some embodiments of the present application, the reaction temperature is 80-100 DEG C.

[0031] According to some embodiments of the present application, the reaction is applied with stirring at a speed of 100-500 rpm.

[0032] According to some embodiments of the present application, the stirring time during the reaction is 1-2 hours.

[0033] According to some embodiments of the present application, the mixing process is carried out under heating.

[0034] According to some embodiments of the present application, the heating temperature during the mixing process is 100-130 DEG C.

[0035] According to some embodiments of the present application, the mixing process is applied with stirring at a speed of 300-1000 rpm.

[0036] According to some embodiments of the present application, the stirring time during the mixing process is 2-3 hours.

[0037] The third aspect of the present application provides the use of the above-mentioned water-based ink efficient defoamer in water-based ink.

[0038] According to some embodiments of the present application, the water-based ink includes rosin-based water-based ink, acrylic-based water-based ink, and polyurethane-based water-based ink.

[0039] According to some embodiments of the present application, the water-based ink efficient defoamer can be used in different sections such as water-based resin polymerization, colorant grinding, ink dispensing, and post-printing addition.

[0040] The water-based ink efficient defoamer of the present application has an addition amount of 0.05-0.3% of the mass of the water-based ink.

[0041] The above technical solution of the present application has at least the following technical effects or advantages compared with the prior art:

[0042] The water-based ink efficient defoamer of the present application has at least the following beneficial effects:

[0043] For the defoaming agent, the defoaming agent needs to have certain incompatibility with the foaming system, so that the defoaming agent can exist in the form of droplets / particles with certain structure and particle size on the gas-liquid interface, that is, the bubble surface, in the foaming system. The surface tension of the defoaming agent needs to be lower than that of the foaming liquid. Due to the lower surface tension, the defoaming agent component existing on the bubble surface causes the bubble surface tension difference, leading to bubble rupture, and the foam is eliminated. At the same time, the lower surface tension and incompatibility can avoid the problem of poor defoaming effect caused by the emulsification and coating of the defoaming agent component by the surfactant on the surface of the foaming system to a greater extent. In addition, the defoaming agent also needs to have good migration ability and can quickly migrate to the gas-liquid interface, that is, the bubble surface, so as to play a rapid defoaming effect.

[0044] In the preparation raw material of the water-based ink high-efficiency defoaming agent, the end polyether modified polysiloxane has a structure of R-A-R, wherein A is a polysiloxane segment, which belongs to a hydrophobic segment (not hydrophilic), and R is a polyether segment. The structure of R can be divided into -PO-EO structure or -EO-PO structure. PO is (OCH(CH3)CH2), which is a hydrophobic segment, and EO is (OCH2CH2), which is a hydrophilic segment. The hydrophobic A segment and the hydrophobic PO segment are linked together to form a whole hydrophobic segment, and the hydrophilic EO segment is at both ends of the molecular chain to form an EO-PO-A-PO-EO structure. One of the characteristics of this structure is that it can automatically form a regular "book pin" arrangement in a water system. EO enters the water phase, while PO and A segments are directed towards the air or the inside of the bubble. Through the difference in surface tension, the fine foam is forced to break quickly and aggregate with each other to form large bubbles, thereby realizing rapid defoaming and persistent foam suppression of the water-based ink system. However, if it is a PO-EO-A-EO-PO structure, it cannot form a regular "book pin" arrangement and is disordered in the system, which greatly reduces the defoaming performance. The second characteristic of the EO-PO-A-PO-EO structure is good compatibility with the water-based ink system, which is not easy to cause the paint film defects of shrinkage and gloss reduction of the water-based ink. The third characteristic of the EO-PO-A-PO-EO structure is good pigment dispersibility, which can effectively prevent the occurrence of printing defects such as "floating color" and "flowering" caused by circulation and turbulence of the water-based ink system.

[0045] In the preparation raw material of the water-based ink high-efficiency defoaming agent, the polyether modified heptamethyltrisiloxane has an umbrella-like structure. One of the structure characteristics is that the surface tension is very low, lower than 22 mN / m, while the surface tension of the water-based ink is generally above 29 mN / m, which meets the requirement of "lower surface tension than the foaming system" in the defoaming mechanism. The second structure characteristic is strong migration ability, which has very strong migration ability, meeting the requirement of "good migration ability" in the defoaming mechanism. The third structure characteristic is good compatibility with the water-based ink system, which is not easy to cause the paint film defects of shrinkage and orange peel of the water-based ink, and does not affect the friction coefficient of the paint film.

[0046] The organic polysilazane resin in the preparation raw material of the water-based ink high-efficiency defoaming agent has reactivity, and in the defoaming agent preparation process, the terminal hydroxyl groups of the polyether in the polyether-modified polysiloxane and the polyether-modified heptamethyltrisiloxane both are subjected to condensation reaction, forming an organic / inorganic semi-interpenetrating network structure of the organic silicon macromolecular mixture, which not only enhances the hydrophobic performance of the defoaming agent system, but also greatly enhances the persistent foam inhibition capacity of the defoaming agent in the water-based ink system; at the same time, the formed organic / inorganic semi-interpenetrating network structure can also effectively enhance the waterproof, oil-proof and antifouling effects of the printed matter.

[0047] In the preparation raw material of the water-based ink high-efficiency defoaming agent, the surface of the fumed nano-silicon dioxide is subjected to hydrophobic modification, and as a defoaming particle, the fumed nano-silicon dioxide is like a needle to pierce the bubbles in the water-based ink system, and plays a role of rapid bubble breaking. At the same time, through the hydrophobic modified surface of the organic silicon and the nano small size effect, the fumed nano-silicon dioxide has good system compatibility and binding force with the polyether-modified polysiloxane and the polyether-modified heptamethyltrisiloxane, so as to prevent the defoaming agent system from being stratified and affecting the gloss of the water-based ink system.

[0048] Therefore, the above preparation raw material has the effect that the water-based ink high-efficiency defoaming agent of the present application has extremely strong defoaming capacity, and only a very low amount is needed to effectively control the foam generated in each production link and use process of the water-based ink. In addition, the defoaming agent has long-acting property, and once added, it can meet the needs of foam control in the whole production and use cycle of the water-based ink, greatly saving labor and cost. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is the system compatibility test of Example 2.

[0050] Figure 2 is the system compatibility test of Comparative Example 2. DETAILED DESCRIPTION

[0051] The present application is specifically described by the following examples in order to facilitate the understanding of the present application by the person skilled in the art. It is necessary to particularly point out that the examples are only used to further illustrate the present application, and cannot be understood as limiting the protection scope of the present application. The non-essential improvements and adjustments of the present application made by the person skilled in the art according to the above application content should still belong to the protection scope of the present application. At the same time, the raw materials mentioned below which are not specifically described are all commercially available products, and the process steps or preparation methods which are not specifically mentioned are all known process steps or preparation methods to the person skilled in the art.

[0052] The main raw materials used in the examples and comparative examples and their manufacturers are as follows: end-polyether modified polysiloxane and polyether modified heptamethyltrisiloxane are purchased from Guangdong Provincial Institute of Chemical Industry; organopolysilazane resin is purchased from Merck Company of Germany; hydrophobic modified fumed nano-silica is purchased from Degussa Company of Germany.

[0053] Example 1

[0054] In this example, a water-based ink efficient defoamer is prepared, and the specific process is as follows:

[0055] (1) In a 1000 mL four-necked flask reactor equipped with an electric stirrer, a reflux condenser, a thermometer, a dropping balance pipe, a N2 gas pipe and an electric heating jacket, 350 g of end-polyether modified polysiloxane C-9937 and 315 g of polyether modified heptamethyltrisiloxane SP-5122 are first added, N2 gas is introduced, and stirring is carried out at 100 r / min. When the temperature reaches 100 ℃, 3.5 g of organopolysilazane resin Durazane® 1500 RC is slowly added dropwise, the dropping time is 10 min, and stirring is carried out at 100 ℃ and 300 r / min for 1 h.

[0056] (2) The stirring and N2 gas are turned off, 31.5 g of hydrophobic modified fumed nano-silica AEROSIL ® R8200 is added to the flask, stirring is started at 500 r / min, and the temperature is raised to 120 ℃ for 2.5 h of continuous reaction, and then the temperature is lowered to room temperature to obtain the water-based ink efficient defoamer of the present application.

[0057] The structure of the end-polyether modified polysiloxane is as shown in the following formula:

[0058] ,

[0059] R is -(CH2)3 (OCH(CH3)CH2)5OH, and n = 5;

[0060] The structure of the polyether modified heptamethyltrisiloxane is as shown in the following formula:

[0061] ,

[0062] Y is -(CH2)3 (OCH(CH3)CH2) 15 (OCH2CH2)5OH.

[0063] Example 2

[0064] In this example, a water-based ink efficient defoamer is prepared, and the specific process is as follows:

[0065] (1) In a 1000 mL four-necked flask reactor equipped with an electric stirrer, reflux condenser, thermometer, dropping funnel, N2inlet tube and electric heating mantle, 490 g of the end polyether-modified polysiloxane C-9921, 175 g of the polyether-modified heptamethyltrisiloxane SP-5150 were first added, N2was introduced, and stirring was performed at 300 r / min. When the temperature reached 80 ℃, 14 g of the organic polysilazane resin Durazane® 1800 was slowly added dropwise, the dropping time was 15 min, the temperature was raised to 90 ℃, and stirring was performed at 300 r / min for 1.5 h.

[0066] (2) The stirring and N2were turned off, 21 g of the hydrophobic modified fumed nano-silica AEROSIL ® R974 was added to the flask, the stirring was started at 800 r / min, the temperature was raised to 100 ℃, and the reaction was continued for 2 h. The temperature was then lowered to room temperature to obtain the water-based ink high-efficiency defoamer of the present application.

[0067] The structure of the end polyether-modified polysiloxane is as shown in the following formula:

[0068]

[0069] R is -(CH2)3(OCH(CH3)CH2) 15 (OCH2CH2)5OH, n = 80;

[0070] The structure of the polyether-modified heptamethyltrisiloxane is as shown in the following formula:

[0071]

[0072] Y is -(CH2)3(OCH(CH3)CH2)5OH.

[0073] Example 3

[0074] The water-based ink high-efficiency defoamer was prepared according to the following specific process:

[0075] (1) In a 1000 mL four-necked flask reactor equipped with an electric stirrer, reflux condenser, thermometer, dropping funnel, N2inlet tube and electric heating mantle, 490 g of the end polyether-modified polysiloxane C-9921, 175 g of the polyether-modified heptamethyltrisiloxane SP-5150 were first added, N2was introduced, and stirring was performed at 300 r / min. When the temperature reached 80 ℃, 14 g of the organic polysilazane resin Durazane® 1800 was slowly added dropwise, the dropping time was 15 min, the temperature was raised to 90 ℃, and stirring was performed at 300 r / min for 1.5 h.

[0076] ​​(2) Close the stirring and N2 gas, add 56 g hydrophobic modified fumed nano-silica AEROSIL ® R972, start stirring to 1000 r / min and warm up to 120°C, continue to react for 3 h, cool to room temperature, to obtain the water-based ink high-efficiency defoamer of the present application.

[0077] The structure of the end-polyether modified polysiloxane is as shown in the following formula:

[0078] ,

[0079] R is -(CH2)3(OCH(CH3)CH2) 10 (OCH2CH2)3OH, n = 30;

[0080] The structure of the polyether modified heptamethyltrisiloxane is as shown in the following formula:

[0081] ,

[0082] Y is -(CH2)3(OCH(CH3)CH2) 12 (OCH2CH2)2OH.

[0083] Example 4

[0084] The water-based ink high-efficiency defoamer is prepared in this example, and the specific process is as follows:

[0085] (1) In a 1000 mL four-necked flask reactor equipped with an electric stirrer, a reflux condenser, a thermometer, a dropping balance pipe, a N2 gas guide pipe and an electric heating jacket, first add 420 g of end-polyether modified polysiloxane C-9965 and 217 g of polyether modified heptamethyltrisiloxane SP-5132, and then introduce N2 gas and stir at 150 r / min to warm up. When the temperature reaches 80°C, slowly drop 21 g of organic polysilazane resin Durazane® 1500RC for 15 min, and then warm up to 120°C and stir at 300 r / min to react for 2 h.

[0086] (2) Close the stirring and N2 gas, add 56 g hydrophobic modified fumed nano-silica AEROSIL ® R812S, start stirring to 900 r / min and warm up to 130°C, continue to react for 3 h, cool to room temperature, to obtain the water-based ink high-efficiency defoamer of the present application.

[0087] The structure of the end-polyether modified polysiloxane is as shown in the following formula:

[0088] ,

[0089] R is -(CH2)3(OCH(CH3)CH2) 15 (OCH2CH2)3OH, n = 50;

[0090] The structure of the polyether-modified heptamethyltrisiloxane is shown in the following formula:

[0091] ,

[0092] Y is -(CH2)3(OCH(CH3)CH2) 12 OH.

[0093] Comparative Example 1

[0094] Comparative Example 1 differs from Example 2 in that no organic polysilazane resin Durazane® 1800 is added to the raw materials for preparing the water-based ink defoamer of Comparative Example 1, and the compositions and amounts of the other raw materials and the method for preparing the water-based ink defoamer are the same as in Example 2.

[0095] Comparative Example 2

[0096] Comparative Example 2 differs from Example 2 in that no polyether-modified heptamethyltrisiloxane SP-5150 is added to the raw materials for preparing the water-based ink defoamer of Comparative Example 2, the amount of end-polyether-modified polysiloxane C-9921 is adjusted from 490 g to 665 g, and the compositions and amounts of the other raw materials and the method for preparing the water-based ink defoamer are the same as in Example 2.

[0097] Comparative Example 3

[0098] Comparative Example 2 differs from Example 2 in that no end-polyether-modified polysiloxane C-9921 is added to the raw materials for preparing the water-based ink defoamer of Comparative Example 2, the amount of polyether-modified heptamethyltrisiloxane SP-5150 is adjusted from 175 g to 665 g, and the compositions and amounts of the other raw materials and the method for preparing the water-based ink defoamer are the same as in Example 2.

[0099] Comparative Example 4

[0100] A water-based ink defoamer is prepared according to the following specific process:

[0101] (1) Preparation of polyether-modified silicone oil:

[0102] Take 40 g of hydrogen-containing silicone oil with a hydrogen content of 0.08%, add 24 g of allyl polyether (EO / PO block polyether, the molar ratio of EO / PO is 1:3, methyl-terminated, molecular weight 300), so that the molar ratio of Si-H in the hydrogen-containing silicone oil to CH2=CH in the allyl polyether is 1:2.5. Add 168 μL of platinum metal (the mass of platinum metal accounts for 10 x 10 - 6wt%), and the reaction was carried out at 100°C for 6h. When the conversion rate reached 98% or more, the reaction was stopped, and the product was discharged after being cooled to room temperature. Thus, the polyether-modified silicone oil was prepared.

[0103] (2) Preparation of the defoaming agent:

[0104] The 20g nanosilica powder was mixed with 3g silazane, and the mixture was reacted at 100°C for 4h to obtain the silazane-modified nanosilica powder. Then, 90g of the polyether-modified silicone oil was added, and the mixture was uniformly mixed and heated to 150°C for 3h. Thus, the silicone paste of the polyether-modified silicone oil was obtained, which was the defoaming agent for water-based ink of the present comparative example.

[0105] Performance test

[0106] The defoaming agents for water-based ink of Examples 1-4 and Comparative Examples 1-4 were subjected to the following performance tests.

[0107] In a 500mL beaker, 200g of red acrylic water-based ink without the defoaming agent was added, and 0.2g of the defoaming agent for water-based ink was added. The mixture was uniformly dispersed at a high speed of 3000r / min for 15min. Then, the stirring was stopped, and the following tests were performed.

[0108] (1) Defoaming property test: the density of the ground water-based ink was tested by weighing within 5min;

[0109] (2) System compatibility test: a 20μm wire bar was used to draw the ground water-based ink on a standard card. The flatness of the coating film was observed, and the gloss of the coating film was tested. According to the overall situation, the system compatibility was divided into five levels, wherein 1st level = good compatibility, no obvious paint film defects such as shrinkage; 2nd level = better compatibility, slight shrinkage of the coating film; 3rd level = general compatibility, shrinkage of the coating film; 4th level = poor compatibility, serious shrinkage of the coating film; and 5th level = poor compatibility, serious shrinkage of the coating film.

[0110] (3) Defoaming capacity test: 50g of red acrylic water-based ink without high-speed dispersion was added to a 500mL graduated cylinder, and 50g of tap water was added. Air was blown into the water-based ink at a speed of 3L / min. When the amount of bubbles reached the 500mL level, the air blowing was stopped, and 0.05g of the defoaming agent was accurately weighed and added into the graduated cylinder. The time required for the bubbles to be completely eliminated was measured.

[0111] (4) Foam suppression test: 50g of red acrylic water-based ink after high-speed dispersion was diluted with 50g of tap water, and the mixture was poured into a 500mL graduated cylinder. Air was blown into the water-based ink at a speed of 3L / min. The height of the foam was recorded every 30min, and the recording was performed for 3h.

[0112] (5) Storage stability test: take 50 g of red acrylic ink after high-speed dispersion, seal and put into 54 °C oven constant temperature for 14 d, then add 50 g of tap water dilution, pour into 500 mL graduated cylinder, adopt drum head with 3 L / min gas flow to drum gas in water-based ink, record the foam height every 30 min, a total of 3 h.

[0113] Table 1 Comparison of defoamer sample performance test results of each example and comparative example

[0114]

[0115] The gloss of the red acrylic ink before high-speed dispersion is 86°

[0116] As can be seen from Table 1, the water-based ink high-efficiency defoamer prepared by Examples 1-4 of the present application is much better than Comparative Examples 1-4 in various performances. Among them:

[0117] (1) From the density test results, the density of Examples 1-4 is greater than 1 g / mL, while the density of Comparative Examples 1-4 is less than 1 g / mL; from the defoaming capacity test results, the defoaming time of Examples 1-4 is completed within 15 s, which is much better than Comparative Examples 1-4. It shows that the defoaming force of Examples 1-4 is much better than Comparative Examples 1-4.

[0118] (2) From the foam suppression capacity test results, the total height of the foam of Examples 1-4 is controlled within 250 mL after 3 h of continuous bubbling, and the foam height rise is less than 100 mL compared with the initial 1 min, which reflects the superior foam suppression performance; the foam suppression time of Comparative Examples 1-4 is less than 80 min, and the graduated cylinder is already overflowing, among which Comparative Example 1 does not use organic polysilazane resin, and the defoamer system cannot form an organic / inorganic semi-interpenetrating network structure, so the foam suppression performance is greatly reduced; the foam suppression capacity of Comparative Examples 2 and 3 is far inferior to that of the examples, which proves that there is a significant synergistic foam suppression effect between the terminal polyether modified polysiloxane and the polyether modified heptamethyltrisiloxane used in this project; Comparative Example 4 uses a comb-like structure of polyether modified silicone oil as the main defoaming component, which has poor migration ability in water-based ink, and its foam suppression time is only 49 min, which is already overflowing the graduated cylinder, and the foam suppression capacity is the worst.

[0119] (3) From the storage stability test results of examples 1~4 and comparative examples 1~4, it can be seen that the end polyether modified polysiloxane and polyether modified heptamethyltrisiloxane with specific structure used in the present application have synergistic effect under the cross-linking action of the organic polysilazane resin, far superior to the effect of single component, have excellent storage stability and long-lasting foam inhibition in the water-based ink system, and realize the need of foam control in the whole water-based ink production and use process by once addition.

[0120] (4) From table 1, it can be seen that the water-based ink high-efficiency defoamer of the present application has good system compatibility, and the coating film has no obvious paint film defects such as shrinkage cavity, and also does not reduce the gloss of the coating film.

[0121] The present application has been described in detail above in combination with examples, but the present application is not limited to the above examples, and various changes can be made within the knowledge range possessed by those skilled in the art without departing from the gist of the present application.

Claims

1. An aqueous ink high-efficiency defoamer, characterized by The defoaming agent is made of 40-80 parts of end polyether modified polysiloxane, 10-50 parts of polyether modified heptamethyltrisiloxane, 0.2-10 parts of organic polysilazane resin and 1-15 parts of hydrophobic modified fumed nano silica by weight fraction; The end polyether modified polysiloxane has the structure as shown below: ， wherein R is -(CH2)3(OCH(CH3)CH2) a (OCH2CH2) b OH, n is 5 to 80, a is 5 to 15, and b is 0 to 5; The polyether modified heptamethyltrisiloxane has the structure as shown below: ， wherein Y is -(CH2)3(OCH(CH3)CH2) e (OCH2CH2) f OH, e is 5 to 15, and f is 0 to 5.

2. The aqueous ink high efficiency defoamer according to claim 1, characterized in that, The preparation method of the water-based ink efficient defoaming agent is: Under the condition of nitrogen, the end polyether modified polysiloxane, polyether modified heptamethyltrisiloxane and organic polysilazane resin are heated and stirred to react, and then the hydrophobic modified fumed nano silica is added and heated to mix and stir, so as to obtain the water-based ink efficient defoaming agent.

3. The aqueous ink high efficiency defoamer according to claim 2, characterized in that, In the preparation method, the temperature of heating and stirring is 80-100℃, the time is 1-2h, and the speed is 100-500rpm.

4. The aqueous ink high efficiency defoamer according to claim 2, characterized in that, In the preparation method, the temperature of heating and stirring is 100-130℃, the time is 2-3h, and the speed is 300-1000rpm.

5. The water-based ink efficient defoaming agent according to any one of claims 1-4 is applied in water-based ink.

6. Use of the aqueous ink high-efficiency defoamer according to claim 5 in an aqueous ink, characterized in that, The water-based ink includes rosin-based water-based ink, acrylic-based water-based ink and polyurethane-based water-based ink.

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